Objectives: Short sleep duration has been linked with obesity in general population, but this issue has not been addressed in patients with obstructive sleep apnoea syndrome (OSAS) separately. Depressive symptoms are frequent in OSAS and may affect sleep and energy balance. Our purpose was to assess the association of habitual sleep duration, psychological distress, depressive symptoms, and excessive daytime sleepiness with measures of obesity in patients with OSAS. Methods: 210 middle aged consecutive patients (111 men and 99 women) referred for evaluation of suspected OSAS were divided into subgroups based on apnoea-hypopnoea index (AHI) and treatment suggested by a sleep physician. Results: OSAS (AHI > 5/h plus symptoms) was diagnosed in 75.7% of the patients. Their sleep duration correlated negatively with psychological distress (r = -0.22, p = 0.043) and depressive symptoms (r = -0.27, p = 0.013) in men. No association was found between self-reported habitual sleep duration and measures of obesity or subjective sleepiness. In patients considered for CPAP therapy, sleep duration associated inversely with depressive symptoms both in men (r = -0.28, p = 0.024) and women (r = -0.33, p = 0.037). After adjusting for age and Epworth Sleepiness Score, the results remained essentially similar. Conclusions: Our results suggest that self-reported habitual sleep duration does not associate with obesity in patients with OSAS. Shorter habitual sleep duration seems to associate with higher scores of depressive symptoms and psychological distress. © 2013 Asian Oceanian Association for the Study of Obesity.